Paint-removing compositions, also known as paint strippers and paint stripping compositions, are used to remove dried films of paint, varnish, or shellac from various substrates including but not limited to wood, metal, concrete, cement, brick, glass, and many organic polymers Typically the paint removing composition is applied to the dried film and allowed to remain for a period of time while the composition attacks the film. After the film has been loosened, the composition and the loose film is removed from the substrate by light scraping (as with a putty knife), wiping and/or washing.
Most of the widely used and accepted paint removing compositions contain methylene chloride (viz., dichloromethane) because of the ability of this compound to efficiently solvate or dissolve a wide variety of paint, varnish, and shellac binders or saponification residues of such binders. Paint removing compositions in general, and methylene chloride based paint removing compositions in particular, are discussed in "Paint and Varnish Removers", Kirk-Othmer Encyclopedia of Chemical Technology, 3d Ed, John Wiley & Sons, New York, 1981, pages 762-768.
The ongoing toxicological testing of methylene chloride by various investigators, however, has produced an accumulation of results raising questions of safety in using methylene chloride for many purposes including its use as a component of paint removing compositions. This has prompted a search for a compound or mixture of compounds which may be substituted for methylene chloride in paint removing compositions and yet function at least about as effectively as methylene chloride with respect to most paint, varnish, and shellac films. Some compounds are known which are very effective, but because they have toxicological problems of their own, or because of their high cost, they are not commercially acceptable.